Microholographic storage in photopolymers

A novel approach to 3D optical information storage based on writing and reading of microscopic holographic gratings in a photopolymer layer is investigated. The reflection gratings created by a highly focused laser beam can be used to replace the pit-land structure in a disk-based optical storage system. The modulation range of such 3D microgratings is clearly localized to the focal region of a focused write beam. Holographic recording allows for use of various multiplexing methods. To achieve storage densities higher than are currently available, we propose a combination of wavelength multiplexing and multilayer storage. Multiwavelength recording in DuPont HRF polymers as well as multilayer storage in thick samples of Aprilis CROP photopolymers are reported.